'Lime Kilns at Northfleet', Kent, 19th century.
© Science Museum / Science & Society Picture Library
Engraving by W B Cooke after an original drawing by S Owen. Lime is used in the building trade for the manufacture of cement and mortar, and also in agriculture as a fertilizer. From the 16th century onwards, lime was extracted by burning coal and chalk in a kiln of the type shown here. The coal and chalk was layered in the kiln, and after lighting it was covered with turf and left to burn for a week or so.